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Sunday, May 15, 2011

Fukushima reactor 1 back to square 1

Any hope of bringing wayward Fukushima Daiichi reactor unit 1 under control has been dashed with the news that the radiation level on the ground floor of the reactor building is 2 sieverts an hour. The current worker dose limit being used by the Japanese government -- and it's lax by international standards -- is 0.25 sieverts a year. Do the math: Any worker going into that building will get a year's maximum dose in 7 minutes and 30 seconds. They're not going to rebuild the cooling system for that reactor under those conditions, or probably ever.

This is the same reactor that Tokyo Electric was making a big show about a week or two ago when they set up an air filtration system in the turbine building that was supposed to make that part of the plant less lethal to occupy. The usefulness of that effort now seems much diminished.

Coupled with this week's news that the fuel rod section of the unit 1 reactor core has been completely without cooling water for nearly two months, the situation is not only completely uncharted territory, but also a challenge beyond the current limits of human engineering. The containment has been breached, and there's a blob of deadly, superheated, melted fuel sitting on the bottom of the reactor, covered at least to some extent by water. There's a good chance that some radioactive lava has oozed out past the steel shell of the reactor and onto the concrete pad below it. Even if it just wallows there, it has to be doused constantly with water, which has become highly contaminated and leaked into the building basement and beyond, into the groundwater and the ocean.

The groundwater under the plant has not been tested, or if it has, the results have been kept secret by Tokyo Electric and the Japanese government. But all sorts of radioactivity has clearly been detected in the ocean near the plant, and the contaminated leakage is relentless.

And that's just unit 1. Reactors 2, 3, and 4 also have serious problems -- perhaps even more serious than no. 1. Knowledgeable observers continue to fret about more hydrogen explosions like the ones that have already ruined the countryside and sent radioactive clouds around the globe -- giant dirty bombs, in effect.

The evacuation zone due to the airborne releases keeps getting bigger, but children attending school just outside the zone are being subjected to radiation exposure that is unconscionable. Meanwhile, they found radioactive cesium in tea leaves grown south of Tokyo, at Minamiashigara, which is more than 170 miles away from the meltdown. The Japanese powers would like to ignore what's happened and what's continuing to happen, but the laws of nature that have been violated aren't going to let them do that forever.

The nucle-heads in the United States are also feeling a bit uncomfortable these days, as they don't have answers for some obvious questions. There are 35 boiling water reactors currently operating in our country -- 23 of them are GE Mark I reactors like the ones that have gone kerblooey in Japan. Current U.S. rules require plant operators to have at least four hours' worth of battery power on hand to run cooling pumps in case of a disaster that causes a complete blackout of the reactor plant and wipes out the on-site diesel generators. Is four hours enough? It wasn't at Fukushima.

And however sturdy the Mark I reactor vessels might be -- they weren't strong enough at Fukushima -- the spent fuel pools in the reactor buildings are incredibly vulnerable. They keep telling us that the reactor vessel can withstand a direct hit from a fully loaded 747. The same assertion cannot be made of the spent fuel pools, and as we now know from Fukushima Daiichi no. 4, those can be a colossal headache even if the reactor isn't running when the disaster hits. Let's hope all those heavy cockpit doors work.

Comments (27)

I've also read that #4 is leaning and the entire building could fall over. Oh, and this weekend there was another 6.2 quake centered 57 miles away.

By now, we needed to be heading for my favorite new term - "cold shutdown"- but another phrase is starting to show up more often in these stories: "Radioactive lava."

We should have known the announced timetable of 6 to 9 months for ending this nightmare, was bogus. When that came out, it seemed outrageously long but more and more, I read that this will continue cooking away for years. The "6 to 9 months" story could have been one of those times when they admit to a damning lie, to deflect from a much worse truth.

I wonder if one of these will ever get so bad that the geniuses in charge would contemplate ending it quickly no matter what. Take the damage but get it over with. At least put the stuff into the atmosphere and spread it out so it can stop interacting. Do you see where I'm going with that? One big explosion to flip the off switch. There's a lot of different advisors involved here. Maybe there's a Dr. Strangelove in the mix.

What would be the analogy for this? It's sort of like cancer. The reactor was a tumor that metastasized and it's spreading out causing more cancer in other places - namely people. The tumor is defying all attempts at treatment and has to come out.

That's why I brought up the nuclear option. And that name has never been more appropriate. But I know...that would be crazy. Drop a bomb on this to make it stop? There has to be a better way, but what is it?

That would mean in cancer parlance that this thing is inoperable. We just have to fight it with holistic measures like seaweed, etc.. and hope it doesn't kill us.

I've had 2 points of greatest concern here. The first was early on when I read the emergency response was to send a fire truck. A fire truck?

The second was the other day when they described the plan to put the whole thing in a tent. The readings at the plant may be at a high point, but that was a low point for me.

Serious, indeed! If the "Nuclear Option" were controllable, then maybe, but what's the difference between the pile going critical and dropping a bomb on it? Only the scattering pattern.

BTW, Jack, the melting point of Uranium is 1132C, the boiling point of water is 100C. There is a discontinuity here. It cannot be both melted and covered by water, even partially. At least when open to the atmosphere.

The blob may have a cool crust on the top, I suppose. It's not all uranium, by a long shot. There are zirconium fuel rod cladding, melted fuel rods, melted core structure, and fission byproducts in the molten corium as well. Moreover, the vessel may be at a pressure above atmosphere, which would change the boiling point of the water. In any event, there's no doubt a whole mess of radioactive steam being created as well.

Lawrence,
I'm not advocating dropping the big one on it. I just find it unbelievable to think that if we had to shut it down this week, we'd quickly get down to options like that. I mean how else do we stop it in a timely manner? Page Superman?

Jack - 2 Sieverts per hour measured by a survey device, is completely different from .25 Sieverts per yer measured by a dosimeter or film badge that measures absorption. There is little correlation between the two. If you are going to make assumptions and claims you had better know what the information means.

Survey devices - like a Geiger Counter - have different efficiencies, and accuracies based upon their detector - of which they are many kinds and styles. Most survey devices look for contamination, not dose, so your preconceived ideas about the dangers of exposure are why off base.

In all fairness you have no idea of what kind or type of survey and measurement devices are used so your jumping to conclusions about future contamination and long term risks are greatly exaggerated. Remember Japan is a country that considers Radon Baths a luxury, and did we bomb the island with a couple of Nuclear devices 60 years ago.

You also have no idea what isotopes have contaminated the area & Buildings other than I-131, Strontium, Cs-137, & Cs-134, etc.

There are plenty of independent Physicists to tell us the truth, without the blogosphere winding everyone up with conspiracy theory's. The fact is no one knows about the long term effects of this kind of radiation accident, but they are never as bad as predicted by the media or the pundits.

A sievert is a measurement of dose equivalent radiation. Tokyo Electric tells us that the dose equivalent radiation inside the building is 2000 millisieverts an hour. If you have a problem with that number, you might want to complain to Tokyo Electric, which is publishing it.

other than I-131, Strontium, Cs-137, & Cs-134, etc.

Since those radioisotopes are more than enough to kill you, I'll stop there.

plenty of independent Physicists to tell us the truth

Unfortunately, when it comes to nuclear power, that simply isn't true. And if these mythical figures did exist, they're being awfully quiet about the worst nuclear disaster in history.

"It's too complicated for you to understand" is typical nuclear industry horsepuckey that isn't anywhere near strong enough to cover up what's happened in Japan. Nice try, though.

If you had a survey meter in one hand and a dosimeter in the other and walked into an area of measurable radiation and your survey meter said you were now standing in a 30 R/hr radiation field, and you stayed there for two hours, then your dosimeter at the end of those two hours would be indicating 60 R. The meter measured the exposure rate or intensity of the radiation there and the dosimeter accumulated the total amount of radiation you had been exposed to for having been there those two hours. (If you had left right after the first half-hour, then your dosimeter would have been reading only 15 R.)

Bottom Line: Both meters and dosimeters have their place, and their limitations, in indicating the presence of hazardous radiation levels, and when utilized by a person with the basic understanding of what they are each measuring, they can be critical life-saving tools to survival in a nuclear emergency.

It's not a simple relationship going on here. Some instruments, like Geiger counters are just that, they count incidences of ionizing particle exposure. They do not give a measure of the energy level of the exposure. A full assessment needs both, to varying degrees depending on the studies intent.

As to the physicists being absent, they generally do not go out on a limb as most other folks do. Look into the literature and you will see much that is being accomplished, but they really stick to their area of expertise. For instance, FermiLab acknowledged the Japanese disaster, but has said zero, as far as I have been able to discern, about the nuclear aspect and I read their daily news about the lab. Seems cold hearted but they are not into nuclear, they are into high energy physics.

I don't want to lower this blog to the level of point/counterpoint (Not that Jack would let me anyway) but it is not inconsistent to have liquid water surrounding materials above 100 C.

Departure from nucleate boiling occurs when a layer of insulating steam forms around and adheres to the hot mass. Heat transfer is markedly reduced. A red-hot poker plunged into water can stay red-hot for a surprising while. Reactor design tries to ensure that this insulating layer does not form along the fuel rods.

I've changed my mind. I say drop the big one on it just to get past these technical comments. Okay, I'm kidding.
Seriously, I got the same thing during the economic meltdown - a lecture for not knowing what this or that instrument was. Meanwhile I resented having to spend 10 minutes trying to figure that stuff out. The suits screwed us on the Wall Street deal and now the lab-coat set is taking a turn.
I'll gladly listen to how the scientists fixed the problem and we all overreacted - so to speak - but until then, it's tough listening to lectures from people who support the side that is currently screwing up. It's not the Sievert Scale that's the problem - it's the Scale of the Screw-Up.

One doesn't need the technical details of the disaster itself to understand the screw-up or it's scale. All one needs to know is the fact that the site was built below the level of a possible tsunami.

They gambled. We lost.

Simple. Tragic.

We also do not need nuclear engineers to explain or explain away the depths of the tragedy. The decisions were made politically, not necessarily on the science. Maybe they were, and the engineers did screw up. Perhaps those who actually built the facility had reassurances that the siting was safe. Maybe they knew and built it anyway. Only a careful investigation would uncover the facts. I wonder if that will ever happen and we are told of the outcome.

I think it is safe to say that there is a lot more of this kind of stuff percolating out there, and we, the public, haven't the foggiest.

Iodine 131, Strontium 82 & 90 are widely used as medical isotopes, and Cesium 137 is widely used for calibration and testing of Radiation Instruments and Survey Equipment.

Up until March 11th any engineer would have been laughed out of the room if he included both an Earthquake and Tsunami happening concurrently in his risk assessment. Obviously it did happen, we learn from it and move on. But we don't condemn new new advancements in technology just because few people have taken the time to learn about it,in fact many have gone out of their way to NOT learn about it. Dams Collapsing, Driving and Tsunamis have caused more death and destruction than the Nuclear Industry.

Look the Fukushima Nuclear Plant is a mess, but it is contained, but the lingering effects will be cleaned up quickly, and effectively - much sooner than the physical, and emotional scars of the disaster.

Comparing a nuclear generating station to a nuclear bomb is like comparing a potato to an oak tree. Yes, they are both organic masses that are created through photosynthesis, but they are completely different.

Nuclear weapons work by creating a supercritical mass - a rapidly increasing chain reaction of fissioning atoms. For each atom that undergoes fission, it causes two or more atoms to undergo fission. It requires a purity of nuclear isotopes and incredibly accurate assembly to actually happen, neither of which occur by accident in a fuel assembly of reactor-grade material.

Nuclear reactors work by bringing enough fissile material together to achieve a self-sustaining chain reaction - for each atom that undergoes fission, it causes another atom to undergo fission.

What they've got there, is a massive mess of fast-fissioning material spread out all over the place. Very deadly to be in the building or around anything that leaves the structure, but you're not going to see a mushroom cloud erupting from Fukushima.

Mark--au contraire! We remember it, and we condemn everything that brought it about. The Japanese protested the siting of these facilities for exactly the two reasons you pointed out, earthquake and tsunami zones . It didn't take an engineer to figure that out, just the local inhabitants. However, politics and greed ruled out. As far as educating oneself, I for one would love to see the top secret documents that the military planners, and G.E. have in their vaults concerning the psycopathic, illegal,and intentional radioactivity releases from Hanford on an unsuspecting downwind populace. I do know that the Yakama's hired a qualified Asian researcher, you know to educate ourselves, back in the 80's. He was illegally, thrown in prison and most of his research was stolen.

I am grateful that Jack's blog is keeping the much needed focus on this issue.

And lest we forget, there are many who will not make it into the statistics: